Moreplay gain questions / Education

Finkle · 2279

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Offline Finkle

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Reply #15 on: September 13, 2024, 03:39:31 AM
I'd have to ask around for one. There's a PC I could try and have been using the record player. The record player is approximately the volume of most music coming thru wired from the phone. I did increase the gain thru the waxwing to 46db to get it increased.



Offline Paul Birkeland

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Reply #16 on: September 13, 2024, 04:44:40 AM
60Hz test track with all volumes maxed including Moreplay. Measuring positive submerged into center of RCA's and negative on the outside, left channels are both showing 3.5V and rights both 9.5V.
This would be bothersome, is the balance pot centered? That's about a 9dB difference.  Are the 10K and 100K potentiometers in the correct holes?  Accidentally swapping these parts can quite the negative impact on how the Moreplay works.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Finkle

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Reply #17 on: September 13, 2024, 05:38:16 AM
The pot is not centered, I manipulated it until the soundstage seemed/felt center. Maybe room gain, as the one side is close-ish to a wall and the other isn't? I'm thinking you're onto something with the pots. Thinking back at the build and not seeing a difference in build I'm feeling like I thought they were the same and I could've swapped them. Looking under the hood at the moment, both pots are stamped with "3ch" and that's it, they look identical. How do I test for which one is which? As I don't think pictures would clear it up, there's no other labels, stamps, manufacture type marks, body are both the same too.



Offline Paul Birkeland

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Reply #18 on: September 13, 2024, 06:52:34 AM
Set your meter to read resistance and measure the resistance between the inner and outer lugs on the top level of the volume pot.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Doc B.

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Reply #19 on: September 13, 2024, 07:10:01 AM
The markings are on the phenolic part of the pots and are facing the chassis plate. PB's suggestion to use a meter is the easiest way to check which is which or you can undo the mounting nut and pull the pot away from the chassis to read the print on the top of the phenolic. Page 20 in the manual explains which is which.

Dan "Doc B." Schmalle
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Bottlehead Corp.


Offline Finkle

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Reply #20 on: September 13, 2024, 08:50:23 AM
A10k is in the volume hole closest to the on off button. Here's some close ups and an overhead.



Offline Finkle

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Reply #21 on: September 13, 2024, 02:58:50 PM
Starting the balance knob in what sounds centered, turning the balance knob towards the left channel it is a much longer rotation to max that direction and it gets very loud like it should at only half volume like a poster said earlier. Going the other way from what I sense as center the knob is already at least 2/3 all the way rotated that direction to get the right speaker sounding balanced. And when turning all the way towards right channel it's a quite short run and doesn't end up nearly as loud as left can go the opposite direction.

Volts going into the preamp from the DAC are identical in both channels. The balance knob definitely isn't turned like that because of room gain, it starts lopsided. So it has to be something in these pictures rights?



Offline Paul Joppa

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Reply #22 on: September 13, 2024, 04:39:15 PM
60Hz test track with all volumes maxed including Moreplay. Measuring positive submerged into center of RCA's and negative on the outside, left channels are both showing 3.5V and rights both 9.5V. measuring the speaker connectors after the buckeye amp speaker wires disconnected from speakers, using test tone, all volumes maxed, positive on red speaker input and neg on black speaker input. Getting 5.51V left channel and 6.47V right channel. When not using the test tone and the loudest sounding track I could find disconnected all speakers again and left side never got higher than 3.8V and right 4.6V. Not sure if I did the speaker test right, what does this all mean or should I test anything differently?
Left channel Moreplay output 3.5v
Left channel  Buckeye output 5.51v
therefore left channel Buckeye gain = 1.57 (about +2dB)

Right channel Moreplay 9.5v
Right Buckeye 6.47v
Buckeye gain 0.68 (about -1.7dB)

Neither of these match the Buckeye amp specs. There's something wrong with the cables or the power amp.

Paul Joppa


Offline Finkle

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Reply #23 on: September 14, 2024, 05:34:19 AM
All volumes max, all outputs disconnected, retesting with balance pot centered. Input from DAC left 1.371 VAC right 1.373 VAC. Outputs on Moreplay left 5.165 VAC both and right 5.644 VAC both. At speaker binding post left 57.79 VAC and right 63.5 VAC. Only thing was 1 or 4 RCA's as output from preamp was kind of loose and was tightened.

Plug in just 2.0 R&L without sub, play music and with the pot centered and they're louder than they ever have been but volume knob at only 20% on Moreplay. Assuming it was a bad solder inspected RCA connectors under the hood and not seeing something obvious. Barely adjust pot to center the sound, not almost all the way one direction like it had been. Plug sub r&l RCA's into Moreplay outputs, turn volume back up and right channel is nowhere...unplug left channel sub output and nothing happens...unplug right sub rca and right speaker comes back strong. Swapped them and it followed the right channel sub connector to whatever side it was plugged into so I'm assuming it's stealing voltage from that channel.

There's a splitter at the sub connecting the Moreplay/stereo system and an AVR. The splitter only was on the right channel RCA and left was plugged directly into sub. Removed the splitter and everything sure seems to be working. Now even with power amp gain at lowest and volume of Moreplay at 50% it's as loud as it had gotten at peak prior.

Thanks everyone for your input, expertise, and concern trying to help me. Everyone's comments helped me understand a bit more what's going on. If some can provide a more detailed explanation of what they assume, math still not adding up, or additional concerns please reach out but thanks again! Now it's time to be worried about the volume knob can do 8)




Offline Finkle

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Reply #24 on: September 14, 2024, 06:34:54 AM
Ps...I wouldn't recommend the UAPP app that was talked about on the first page. Usb Audio Player Pro has crashed nonstop and given far more complexity than it should.